Geology and mineralisation of the Mewet Vein, Jelai Gold Project ...

More documents

Recommendations

Info

PT GMT Indonesia Mewet Vein : Jelai Gold Project 4.4 Physiography Northeast Kalimantan is characterized by jungle covered mountainous terrain. To the north of the project area, near the Malaysian border, the topography is extremely rugged, with elevations up to 2,000 metres and difficult access. The coastline consists of an extensive, well developed estuarine-delta system, with dense palm grove vegetation and swamp development. In the Jelai-Mewet area, the terrain is undulating to rugged, with elevations of up to 1,000 metres on some volcanic peaks. Waterfalls and rapids are developed in the upper reaches of the drainage systems, posing access problems in some areas. However, in the prospect area itself, elevations range up to 200-300 metres with a vertical relief of only 150 metres. 0065 JCM/GEO/2009.04 Page 14
PT GMT Indonesia Mewet Vein : Jelai Gold Project 5 5.1 HISTORY Pre-Indochina Exploration Before 1994, there was little sustained systematic exploration of the region by mining companies. Much of Northeast Kalimantan was designated a Reserved Area (CTA 39A) and was not available for mineral exploration. CTA 39A was the reserve for a joint exploration and mapping programme at 1:250,000 scale and a stream sediment geochemical survey conducted by a joint French-Indonesia research team (Bureau de Recherché Geologiques et Mineres and Direktorat Jenderal Pertambang Umum (BRGM/DSDM) during 1979-1986 (reports by Lefevre et al., 1982, Le Bel et al., 1985 & 1986 and Nagel et al., 1987). The BRGM/DSDM regional stream sediment geochemical survey resulted in the discovery of an intrusive-skarn metallogenic province in the Long Laai area (south of Jelai-Mewet). The skarns contain base metal-silver mineralisation associated with tinbearing intrusives. No systematic sampling was undertaken for gold, apart from pan concentrate analysis. Follow up stream sediment sampling in 1:50,000 scale geological mapping were undertaken by the BRGM/DSDM over the Long Laai region (Le Bel et al., 1986) and the Long Bia region (Nael et al., 1987). Drilling was conducted at the Mamak prospect, but the results were disappointing. The epithermal gold potential of north east Kalimantan was first discussed by Mr. D. Kirwin and Mr. A. Beaudoin in 1985 (Kirwin, 1993). RTZ (Rio Tinto) conducted a three month prospecting survey in 1990. The investigation included stream sediment, panned concentrate, stream float, channel sampling and some tape and compass mapping. Drainages investigated included the Sungai Turau, Mewet and Jelei. The results were not considered encouraging at that time for RTZ In 1993, PT Macan Mas Minerindo (Fleming, 1993) conducted a selective reconnaissance survey over areas considered prospective based on the BRGM/DSDM survey results. The reconnaissance survey located epithermal vein quartz in the Sungai Jelei area, silica-pyrite breccias in the Sungai Makjun and Sungai Pangean drainages, presumably base-metal gossan at Gunung Kelapis and confirmed the presence of base metal-silver mineralized skarns at Long Laai. Fleming (1993) indicated that some small scale hard rock gold mining activities were occurring in the Bukit Pondok area associated with previously worked (1902) lead-silver veins. Episodic local alluvial god panning was occurring in the Sungai Makjum, Saling, Betal, Geh, Malinau, Pangean, Segah, Yin and Ptong. 5.2 Indochina Goldfields Exploration A technical recommendation to systematically prospect the region for epithermal gold by Kirwin (1993) was the basis for Indochina committing to exploration in Indonesia. A geological assessment (Sennitt & Kirwin, 1994) and an aerial reconnaissance survey (Kirwin & Sennitt, 1994) were undertaken over parts of the region, in order to confirm the prospectivity for significant precious metal mineralisation. In July, 1994, Indochina Goldfields Ltd. entered into a joint venture agreement, covering three CoW blocks totaling 3 million hectares, in order to explore the region for precious metal mineralization. Work commenced in Sungai Jelai as early as 1995 but it was not until 1995/1996 that the focus shifted to the Sungai Mewet area, where epithermal quartz vein float was found in many streams in the area and precipitated a full detailed geological survey of the area including 0065 JCM/GEO/2009.04 Page 15
Page 1 and 2: GMT I N D O N E S I A PT GMT Indone
Page 3 and 4: PT GMT Indonesia Mewet Vein : Jelai
Page 13: PT GMT Indonesia Mewet Vein : Jelai

Geology and mineralisation of the Mewet Vein, Jelai Gold Project ...

Create successful ePaper yourself

Delete template?

Save as template?